Device for actuating a drop-hammer or the like



Jan. 19, 1965 J. F. M. BAUDRILLARD 3,166,351

DEVICE FOR ACTUATING A DROP-HAMMER OR THE LIKE Filed Oct. 8, 1962 2 Sheets-Sheet 1 INVENTOR FRANCOlS MARCH. BAUDRIUMV 2 ATTORNEYS Jan. 19, 1965 v J. F. M. BAUDRILLARD 3,166,351

DEVICE FOR ACTUATING A DROP-HAMMER OR THE LIKE Filed Oct. 8, 1962 2 Sheets-Sheet 2 Fig.2

INVENTOR J EAN FRANCOIS MARCEL BAUERILLARD wykm ATTORNEYS United States Patent Ofi 3,165,351 Patented Jan. 19, 1965 3,16%,351 DEVICE 1 R ACTUAEENG A DRIBP-HAMMER OR THE LIKE Jean Francois Marcel Baudriiiard, 52 Ave. Egle, Maisom-Lafiitte, France Filed Oct. 8, 1962, Ser. No. 228,989 iaiins priority, appiicaticn France, Oct. 9, 1961,

875,379 4 (Ziaims. (Cl. 2%4-96) The present invention has for its object a mechanical device intended to effect the operation of a drop-hammer or the like, and designed more particularly to carry out the following operations: to engage the drop-hammer when the latter is in its lowermost position, and to lift the hammer up to its top position and subsequently to release it, the device being given for that purpose a vertical reciprocating motion. The engagement and the release of the hammer may be effected automatically at the end of travel of the actuating device by engagement and disengagement of suitably-disposed locking means.

According to one form of embodiment of the invention, the coupling is obtained by a Wedging action of balls or other adequate members co-operating with a cam which, in the active locking position, causes a lateral displacement of the said members and jams them against a part which is rigidly fixed to the drop-hammer, but which can on the other hand be retracted to permit the disengagement of the said members and in consequence the freeing of the hammer.

This cam is preferably arranged on a part which performs the function of a guiding slide for the device in its vertical to-and-fro movement and which is capable of a certain longitudinal displacement with respect to the body of the said'device. A spring interposed between this body and this slide urges the cam towards its operative position. The retraction of the cam is obtained by driving the slide into the body of the device against the action of the spring, for example by means of a stop or abutment which comes into contact with the said slide at the end of the upward travel of the device.

The present invention is adapted to an especially advantageous application for the purpose of testing the resistance of ground by the so-called penetrometer method, by means of a probe which is driven into the ground by letting a drop-hammer of given weight fall from a predetermined height. The invention can also be applied with advantage for use with bells and other devices of the same kind.

The description which follows below with reference to the accompanying drawings (which are given by way of example only and not in any limitative sense) will make it quite clear how the invention may be carried into effect, the special features which are brought out either in the text or in the drawings being understood to form part of the present invention.

FIG. 1 is a perspective view with radial cross-section of one form of embodiment of the device of the invention, mounted on a probe.

FIG. 2 is an axial section of the device showing its two positions of operation.

There can be seen in FIG. 1 a vertical rod 1 forming part of a probe driven into the ground by the action of a drop-hammer 2 through which the rod passes freely and which is provided at its upper portion with a sleeve 3 open at the top. In the example of construction shown in the drawings (see also FIG. 2), this sleeve has an internal surface 3a which is slightly conical and co-operates with a flared opening 311. The rod 1 terminates in a threaded extremity 1a, on which is screwed a nut 4 serving as a limiting stop for the travel of the actuating device of the drop-hammer, indicated in a general manner by the reference letter D. g

This device D comprises a thick ring 5 rigidly fixed on one side to a sleeve 6 and on the other side to a small socket 7 forming a shoulder 7a. On the periphery of this ring 5 is also screwed a cylindrical skirt 8 open at the bottom and having an internal diameter greater than the external diameter of the sleeve 3.

The ring 5 and the associated members 6, 7 and 8 form a body of revolution coaxial with the vertical rod 1, along which it is guided through the intermediary of a tubular slide or guide means 9 passingfreely through the ring 5 and its sleeve 6. The coupling between the body of revolution and the tubular slide is etfected through a coil spring in surrounding the latter and supported on the one hand against the shoulder 7a which forms the bottom of the socket 7, and on the other hand against a circular end-plate i1 rigidly fixed to the slide 9 and located at its upper extremity. At the lower extremity of the slide is screwed a ring 12 provided with an outer sloping face 12a and forming an annular housing 13 in which can engage the lower extremity of the sleeve 6, the penetration being limited by abutment of the sleeve against the bottom 13a of this housing.

Thus, the slide 9 with its terminal ring 12 are capable of a certainaxial displacement with respect to the body S-d-Lti of the device D, this displacement being limited on one hand by abutment of the socket 7 against the endplate 11 (position close to that which is shown on the half-section on the left hand side of FIG. 2 and at which the spring It is compressed) and on the other hand by abutment of the lower extremity of the sleeve 6 against the bottom 13a of the housing 13 (position shown on the half-section on the right hand side of FIG. 2, and also in the perspective view of FIG. 1, and at which the spring 19 is expanded).

In the annular space of the body of the device D, which space is de-limited by the ring 5, the sleeve 6 and the skirt ii, are mounted locking members, for example three in number and arranged at from each other. These members are constituted by balls 14 housed in small tubes 15 provided with lateral slots 15a directed outwards, and through which the ball is adapted to project. This ball is controlled by a spring 16 supported against the bottom of the tube 15 and fixed by a transverse pin 17. This tube is extended by a forked member 18 pivoting about a horizontal shaft 19 carried by a part 20 fixed on the ring 5 by a screw 21.

In this way there is produced a set of three tubes 15 articulated in a way similar to the weight heads of a centrifugal regulator and urged towards the axis of the device D, either by the simple effect of gravity or alternatively by means of a spring (not shown).

The lower edges 15b of these tubes come into abutment against the ring 12 which acts as a cam and, depending on the relative position of the cam, they are held apart or are able to come closer together. In the first position (FIG. 1 and the half-section on the right of FIG. 2), the generator lines of the tubes 15 are considerably inclined to the vertical and the space delimited by the walls of these tubes and the wall 3a of the sleeve 3 becomes smaller from the top to the bottom; this results in a wedging action of the walls 14 when the sleeve 3 and the device D tend to separate from each other and in consequence these two parts become instantaneously locked together. On the other hand, in the second position (half-section on the left hand side of FIG. 2), the came 12 being withdrawn, the generator lines of the tubes 15 are almost vertical and the wedging effect previously described disappears. The device D and the sleeve 3 then become disengaged and can be separated.

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The operation of the drop-hammer by means of the D with the drop-hammer 2-3 (FIG. 1 and the right hand half-section of FIG. 2), the whole assembly is lifted by acting for example on handles 22-22 fixed on the body of the device. At the end of this travel, the end-plate 11 of the slide 9 comes into abutment against the nut 4, and by continuing slightly the lifting movement, the slide 9 is driven into the body of the device D, compressing the spring 10. The cam 12 is then withdrawn downwards and the locking members come into the position shown on the left hand half-section of FIG. 2, freeing the sleeve 3 and permitting the drop-hammer 2 to fall freely in order to produce the driving action on the probe 1. The device D is then lowered so as to re-join the drop-hammer in its bottom position and it is engaged in the sleeve 3. During the course of this latter phase, the slide 9 and the cam 12 having moved back into their position of rest (right-hand half-section of FIG. 2) under the action of the spring 1d, the balls 14 come into engagement with the flared opening 3b of the sleeve; they are then withdrawn into the tubes 15 while compressing their springs 16. The neck of the sleeve 3 is thus passed, the balls 14 remaining constantly in contact with the wall of the sleeve without interfering with the movement of penetration of the device into the sleeve, due to the orientation of the Wedges formed by the tubes 15 and the wall 3a.

The travel of the actuating device is limited at its bottom position by means of a stop or abutment. This member (not shown) is rigidly fixed to the body 567-8 and comes into abutment against the drop-hammer 2, thus fixing the position of the locking members with respect to the sleeve 3 during the phase of operation corresponding to the locking together of the actuating device and the drop-hammer.

As soon as the device D is lifted, the wedging eiiect takes place instantaneously and ensures this locking action without any relative displacement of the locking members and the sleeve 3. The drop-hammer is thus driven and the operation described is repeated.

' What is claimed is:

1. A mechanical device to control the vertical displacement of a drop-hammer along a vertical rod surrounded by the drop hammer comprising, in combination, cylindrical guiding means slidably mounted and longitudinaliy displaceable relative to said rod, an inner sleeve rigidly fixed onto said hammer and provided with a substantially conical inner surface coaxial with said cylindrical guiding means, a movable body slidably mounted relative to said guiding mean-s, engagement means movabiy mounted on said body, cam means fixed on said guiding means and cooperating with said engagement means so that said engagement means engage or disengage instantaneously said conical sleeve for a predetermined position of said body relative to said guiding means, and an adjustable upper abutment, mounted upon said rod, to limit the longitudinal displacement of said guiding means over said rod.

2. A device as in claim 1 in which said cylindrical guiding means comprise a tubular slide provided with an upper collar, a coil spring being disposed around said slide between said upper collar and said movable body.

3. A device as in claim 1 in which said engagement means comprise spring mounted balls and said cam means comprise a substantially conical cam coaxial with said sleeve.

4. A device as in claim 3 in which the conical cam means comprises an annular part providing a lower abutment for said body.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A MECHANICAL DEVICE TO CONTROL THE VERTICAL DISPLACEMENT OF A DROP-HAMMER ALONG A VERTICAL ROD SURROUNDED BY THE DROP HAMMER COMPRISING, IN COMBINATION, CYLINDRICAL GUIDING MEANS SLIDABLY MOUNTED AND LONGITUDINALLY DISPLACEABLE RELATIVE TO SAID ROD, AND INNER SLEEVE RIGIDLY FIXED ONTO SAID HAMMER AND PROVIDED WITH A SUBSTANTIALLY CONICAL INNER SURFACE COAXIAL WITH SAID CYLINDRICAL GUIDING MEANS, A MOVABLE BODY SLIDABLY MOUNTED RELATIVE TO SAID GUIDING MEANS, ENGAGEMENT MEANS MOVABLY MOUNTED ON SAID BODY, CAM MEANS FIXED ON SAID GUIDING MEANS AND COOPERATING WITH SAID ENGAGEMENT MEANS SO THAT SAID ENGAGEMENT MEANS ENGAGE OF DISENGAGE INSTANTANEOUSLY SAID CONICAL SLEEVE FOR A PREDETERMINED POSITION OF SAID BODY RELATIVE TO SAID GUIDING MEANS, AND AN ADJUSTABLE UPPER ABUTMENT, MOUNTED UPON SAID ROD, TO LIMIT THE LONGITUDINAL DISPLACEMENT OF SAID GUIDING MEANS OVER SAID ROD. 